In the related art, there has been put into practice a technique of producing ethanol and the like, in which biomass such as wood is subjected to saccharification processing using dilute sulfuric acid and concentrated sulfuric acid and then subjected to solid-liquid separation, and a liquid phase is neutralized to be utilized as feedstock for ethanol fermentation and the like (Patent Literature 1, Patent Literature 2).
Furthermore, chemical industrial material production (for example, lactic acid fermentation) using saccharide as starting feedstock may also be considered.
Here, the biomass refers to organisms incorporated into the substance circulation system of the earth biosphere, or accumulation of organic materials derived from the organisms (see JIS K 3600 1258).
Here, sugar cane, corn, and the like currently used as alcohol material are originally provided as food, and it is not preferable to use such edible resources as industrial application resources for a long period of time in a stable manner from the perspective of life cycles of useful foodstuffs.
For this reason, it is an important problem to effectively make use of cellulose resources such as herbaceous biomass and woody biomass which are considered to be useful resources in the future.
Furthermore, in the cellulose resources, cellulose is 38 to 50%, and a hemicellulose component is 23 to 32%, which vary, and a lignin component not serving as fermentation feedstock is 15 to 22%, which also varies. Since this is an industrialization study involving many problems, feedstock is considered in a fixed manner, and currently, there has not yet been made any disclosure of a technique of a production system based on consideration of the versatility of feedstock.
Further, originally an aim is considered to cope with waste problem and prevent global warming using feedstock which is more disadvantageous for fermentation feedstock than starch feedstock, and therefore, a production system based on a fixed notion of feedstock is less meaningful. The production system needs to be applicable to a wide range of wastes in general. Currently, an enzymatic saccharification method itself has too low efficiency and is regarded as a future problem. The saccharification rate by acid treatment is a very small value on the order of about 75% (based on components that can be saccharified) because of excessive decomposition of saccharide due to overreaction. Therefore, for the cellulose resources, the ethanol production yield stays at about 25% (Patent Literature 3).
It is noted that in the techniques in the related art of Patent Literatures 1 to 3, side-reaction products have caused enzymatic saccharification inhibition, and there occurs a phenomenon that the saccharide yield decreases, and therefore, a hydrolysis apparatus that removes an enzymatic saccharification inhibition substance and enhances enzymatic saccharification performance for mainly cellulose has been proposed previously (Patent Literatures 4 to 7).